Safety Instructions

55
Plate voltage error
Check plate power supply
High voltage supply fault. Check the fuses on HV board.
Grid voltage is low
Check grid power supply
Low voltage on the grid. Check fuse F9 on HV supply board.
Screen voltage error
Check screen power supply
Check fuse F10 on HV supply board and fuse F1 on the
Screen board.
Amplifier is too hot
Check cooling system
Set up additional blower
Check the airflow (ventilation grid on the rear panel).
Cooling exhaust must be free from any obstructions. During
extended use set the blower speed to ALWAYS ON (page
20).
HARD FAULT
Check HV circuits and Tube
Protection circuit saved HV against overload If high current
from the HV supply caused the HARD FAULT then
protection is activated and the PA is automatically switched
OFF. Check HV circuits, blocking capacitors and the tube
itself.
Heating voltage error
Set up proper transformer
voltage selector
This error is usually due to improper setting of the primary
voltage on the transformer (page 33). In normal condition
Uh readings should be 9V +/- 0,3V
Cooling error
Check blower rotation
Main blower problem. Check its functionality.
Mains error
Check mains voltage and set up
nominal mains voltage Set
up proper transformer voltage
selector
This error may be caused by the improper setting of
the nominal value of Um. Check your AC mains
voltage and set it as nominal Um (page 22,23). Check
the primary voltage setting on the transformer. This
fault may also be caused by “soft” mains, when during
transmitting the AC voltage drops to a very low level.
Factory reset:
In the case of very abnormal behavior of the OM4001A it is possible to do a factory reset. This will reset
all the amplifier parameters back to the factory default values.
Press and hold the ON/OFF button and press the green Main power switch for several seconds until the
following display appears.
If you are sure you want a full factory
reset, press YES.
Type of supported TCVR and
working
frequency are visible on the display.
AUTO LED is ON.